/*
 * Copyright (c) Kumo Inc. and affiliates.
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include <melon/km_string.h>
#include <melon/portability/config.h>

namespace melon {
    inline constexpr size_t demangle_max_symbol_size =
#if defined(MELON_DEMANGLE_MAX_SYMBOL_SIZE)
            MELON_DEMANGLE_MAX_SYMBOL_SIZE;
#else
    0;
#endif

    extern bool const demangle_build_has_cxxabi;
    extern bool const demangle_build_has_liberty;

    /**
     * Return the demangled (prettified) version of a C++ type.
     *
     * This function tries to produce a human-readable type, but the type name will
     * be returned unchanged in case of error or if demangling isn't supported on
     * your system.
     *
     * Use for debugging -- do not rely on demangle() returning anything useful.
     *
     * This function may allocate memory (and therefore throw std::bad_alloc).
     */
    kmstring demangle(const char *name);

    inline kmstring demangle(const std::type_info &type) {
        return demangle(type.name());
    }

    /**
     * Return the demangled (prettified) version of a C++ type in a user-provided
     * buffer.
     *
     * The semantics are the same as for snprintf or strlcpy: bufSize is the size
     * of the buffer, the string is always null-terminated, and the return value is
     * the number of characters (not including the null terminator) that would have
     * been written if the buffer was big enough. (So a return value >= bufSize
     * indicates that the output was truncated)
     *
     * This function does not allocate memory and is async-signal-safe.
     *
     * Note that the underlying function for the kmstring-returning demangle is
     * somewhat standard (abi::__cxa_demangle, which uses malloc), the underlying
     * function for this version is less so (cplus_demangle_v3_callback from
     * libiberty), so it is possible for the kmstring version to work, while this
     * version returns the original, mangled name.
     */
    size_t demangle(const char *name, char *out, size_t outSize);

    inline size_t demangle(const std::type_info &type, char *buf, size_t bufSize) {
        return demangle(type.name(), buf, bufSize);
    }
} // namespace melon
